Embodiments of the invention generally relate to one or more of networks, communication, network elements, methods, apparatuses, systems, radio systems, radio access networks, and programs e.g. for coverage hole detection or hole related processing or operation.
Embodiments of the invention may relate to mobile wireless communications, such as third generation partnership project, 3GPP, long-term evolution (LTE & LTE-A) or any other existing technologies.
Some radio access systems facilitate variable bandwidth support, e.g. on orthogonal frequency division multiplex access, OFDMA, and orthogonal frequency division multiple, OFDM, access air interface concepts. Examples include long-term evolution, LTE, and worldwide interoperability for microwave access, WiMAX, etc.
In some networks, the access apparatus like radio access devices such as NodeBs, NBs, and also home NodeBs or evolved home NodeBs, H(e)NBs, base stations, may be continuously operated. A base station, base transceiver station, or NodeB may have remarkable power consumption when active, and may generate significant operational expenditure due to its power consumption. In addition to the cost aspect for the operator, the ecological impact has to be considered.
At least some radio access systems aim at reducing power consumption of a base station or other access systems like radio systems for operational expenditure, OPEX, and ecological reasons, by means of e.g. temporarily switching off dedicated base stations, BSs, or base transceiver stations, BTSs, and re-configuring other base stations autonomously, to retain the coverage.
A mobile station may be configured to notify a state when it is out of suitable coverage. This may be a state when the mobile station is unable to detect e.g. a broadcast signal with sufficient reception performance. When the mobile station gets back into a state of sufficient radio coverage, the terminal may send a report such as a “coverage hole detected” message to the network. The report receiving entity or the network may in turn deliver this report to an operation and maintenance, O&M, system. At least one of the network and the operation and maintenance system may have means to correct such possible coverage holes, especially if self-configuring and/or self-optimizing network, SON, procedures intentionally have turned off base stations or sectors. The network or operation and maintenance, O&M system, or another entity may then decide based on the report whether or not such an action like switching on again a base station or sector or other type of coverage hole closing or reducing action is justified.
However, a radio coverage loss may not always be caused by a coverage hole, as e.g. caused by a SON measure. There may be random accidental losses, like a mobile was misplaced in an out-of-coverage area such as a closed environment like a garage for a while. Or the terminal may have entered a sub-terrain car park, a subway station, or an elevator, i.e. areas which are part of a calculated outage of the network operators network planning.